Improved latch



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NORWlCl-I, CONNECTICUT.

Letters Patent No. 100,S72, dateZ March 15, 1870.

IMPROVED LATCH.

. To all persons` to whom these presents may-come:

Beit knownithat I, santos W. DROWNE, of N01-- v wich, of the `county of N ew London, of the State of Connecticut, have made a new and useful invention having reference to Locks for` Doors; and Ido hereby declare the same :to be fully described in' the `ollowhrg .speciiication, and represented in `the-accompanyingv drawings, of which y Figure 1 denotes the iuternalarrangement and parts of a` lock `containing my i1ivention-the cover being supposed to be.` removed from the czise.

Figure 2 is a side view of such cover, and Figure 3 isa side View of the key.

Figure 4 is a transverse section of the lock, it being i taken through the-pivot of the 'tumblers The invention consists in the arrangement of a stopslide and a false tumbler, as hereinafter described, with the latch-.bolt and the main or key-tumblers `and separa-te key-holes, the whole being constructed substan- `tially in manner ashereinafter explained.

Thepurpose of the stop-slide is to enable the bolt to be'so locked bythe key, (whenlinserted in the ,lock

from the inside of thedoor,) as to' prevent thebolt from being thrown back by either the outside knob of `the lock, while being revolved, or by a key introduced into theonter key-hole. i

lhe purpose of the false orl auxiliary tumbler, which is in no respectoperated by the real key of the lock, as are the main tumbleia, is to lock the bolt when a false key may be introduced into the lock from the outside -of 'the door and employed in an attempt to throwback the bolt, or when an effort may be made to pick the lock. y

1n tbedrawings- A denotes the box or case of the lock. B, the latch-bolt.`

C, its impelling spring. y Y

C', the cam-piece for retracting the bolt and re ceiving the shank of the knobs.

. In this lock there are two levers or tmnblers, D E,

arranged on a common fulcrum or4 pivot, F, each tumbler being provided with an operative spring, Gr.

What I term the articial tumbler or safety catchplate H, shaped as represented, is Varranged directly i between the main tlimblers and applied so as rto be fcapable of turning on their common pivot.

` 'The safety-plate or artificialtumbler has an operative` spring, I, which extends from its 'heel and rests against the projection K, for receiving the cover-confining screw whichgoes through a hole, a, in the cover L. y, The spring l serves to force the artificial or false tumbler against a stop-stud;7 b, so as to carry a tooth, path oi' moves ment of Athebolt cam-piece C', i i

lhe inner or inside key-hole shown at c is formed` in i `t-he opposite side of the lock-case, so as to open into anopening, f, made in 4the stopeslide M. There is also in each tumbler DE an opening, g, to enable the tumbler to be actuated by the bit of the key.

, The stop-slide, formed and arranged in manner as represented, is to be capable of being moved endwise between guides h 71, h, and has a friction-brake or spring, i, to press against it and hold it in position, as occasion may require. i

On introducing the key into the inner key-hole c, and turning such key so as to revolve its `bits toward the bolt, we shall throw the stop-slide M upward in rear of a shoulder, Z, 'oi' the bolt, so as .to prevent the bolt from being moved by the knobs or the cam-piece thereof, when removed by either knob, and especially the outside one. By turni-ng the key in the opposite direction, the main tumblers 1) E and the stop-slide may be simultaneously moved away from the shoulder l, in order to admit of the bolt being thrown by power applied to the outside knob. i In case of a false key being introduced into the outer keyhole, and with it a`n attempt should be made to move the main tumblers far enough to admit of the retraction of the bolt by moving the outer knob, the` chance `will be that the false tumbler will be thrown up so as to cause its tooth to pass np in rear of the cam-piece in a manner to prevent it from being moved by the piece applied to the" knob.

Thus, it will be perceived, with the stop-slide and the safety or false tumbler combined with the main a iu the-outside key-hole, or the false tumblers may be moved upward by a pick-lock, in expect-ation that it may be one of' the series of key-tumblers necessary to be movcdinto proper positions before the bolt can bc released. l

y The drawings represent a slide-yoke, O, and an auxiliary cam-piece, P, as applied to the latch-bolt, (see Figure 5, which is a horizontal and transverse section of the lock, the section being taken through the bolt.) When the ailxiliary cam-piece and the yoke are employed, the knob-spindle is to be in twoparts, so connected ,that one may be revolved independently of the other, and each actuate its own campiece. 1t is not new to so makea knob-spindle and provide the bolt with a yoke and au auxiliary cam-piece; `therefore, I makeno claim thereto.

With the above-described lock the bolt cannot be I claim the'arrangement of the stop-slide M and actuated by force applied to the outer knob, except the false tumblers H with the latch-bolt B, and the the key be first used in the outer key-hole so as to main or key-tumblers, :md separate key-holes, conaetnate the tumbler-s D E. By throwing up the stopstrueted and arranged in the lock-case substantially slide by :L key introduced into the innerkey-hole, the iu manner as specified.

bolt will be estopp'ed from being retracted by force ap- SIMEON XV. BROWN E. plied to either knob, but when the stop-slide is down, Witnesses:

the bolt may be actuated by force applied t'o the inner R. H. EDDY,

knob.

S. N. PIPER. 

